Improved kiln foe boasting iron ores



@ni-teh tatzs stznt @frn ALOIS THOMA, OF NEW YORK, VN. Y., ASSIGNOP TO HIMSELF, SAMUEL BROMBERG, AND ARTEMUS W. WILDER, OF-'lI-IE SAME'PLACE.

Letters Patent .Na 70,045, dated October 22, 1867.

IMPROVED KILN FOR ROASTING IRON DRES.

TO L'L WHOM IT MAY CONGERN:

Be it known that I, ALoIs TnoMA, OfNew York, in the county and State of. New York, have invented a new and improved Kiln for Roasting Iron Ore; and I do hereby declare that the following is a full, clear, and exact description' thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specilication.

Figure 1 represents a longitudinal vertical section of my invention.

Figurey 2 is a verticahtransversc section of the same.

Figure 3 is a horizontal sectional view of the same, the plane of section'being indicated bythe line 25x, iig. 1.

Figure 4 is ahorizontal sectional view ofthe same, the plane ofsectionbeing indicated by the line yy, g. 2.

Similar letters ot" reference indicate corresponding parts.

-This invention relates to a newl furnace and to a new process for roasting iron ore, said process being particularly applicableto the treatment of magnetic i'ron ore, which is found in large quantities throughout the United States. I

The object of -the'invention is to reduce the expense of the process, andto so arrange-.the .kiin `und the whnle process that the roasting' may be done with rthe use of brown coal, wood, or even peat, while heretofore only the expensive anthracite coal could be used for the purpose. l

The roasting of the iron ores is donc by means of the gases or products of combustion discharged from the Vsmelting-turnace, or otherwise produced. These gases are mixed with atmospheric air, and are ignited within the kiln, thereby more fully and completely roasting the ore than could bc done by any process now in use. The ore is desulphuriz'ed by the application of hydrogen gas, created by the evaporation of water led through the kiln. No'd'irect fuel is used for the roasting process. Provision is made that the supply of air, as well as of gas, can be regulated at will. y

A represents a furnace, made of-re brick or other suitable material, built upon a suitable foundation. It has a base, B, made of octagonal or other suitable shape. The upper part of the furnace is made tubular, the opening being broadest in the centre, and contracting towards the upper and lower ends, as is clearly shown in figs. 1 and 2. In the lower part of the kiln is arranged around the tubular inner opening a channeL'a, of octagonal or other suitable form, as shown by dotted lines in fig. 3. The same communicates by upright channels bwith a series of. horizontal channels, c c, arranged above the channels a, and radiating from the central chani'ber C, as is clearly shown in figs. 1, 2, and 3. The channels c communicate directly with the chamber C and with the outside of the furnace, as shown. Above the channels c are arranged similar radial channels, d d, which also communicate with the outside and with the chamber` G. The bottom of the chamber C is made slanting towards two sides, as shown, to facilitate Vthe discharge of the ore from the chamber C, (see iig. 2.) The crest of this roofshaiped bottom is formed by an iron tubo, e, lperforated at the sides, and extending with one end throughthe sides of the kiln, as in fig. 1. The ore to be roasted is placed into the chamber C, the discharge-channelsf at the bottom of the same beingclosed by massive blocks or doors, g, as shown in iig. 2. The gases or products of combustion discharged vfrogn the Asnelting-furnace, and carried.4 thence through a pipe of suitable length to 'the kiln, enter the channels a a through the pipe h, and pass up throughthe channels 6 into the radial channels c. The channels b may be partly covered by metal plates z'z', to regulate the loW of the gases. A dust-receiver, j,vis arranged below the channels a, and can be emptied from j', iig. 1. The channels a are also provided with openings c k, by which they communicate with the outside, said openings beingrigidly closed by blocks or doors l. They are for the purpose of allowing the cleaning of the channels a. In the channels c gases are mixed `:with `atmospheric air, entering through the outer enis of the channels c, said outer ends being wholly or partly* closed by gates m, by which the quantity of air admitted is regulated. The channels e are widened the nearer they are to the chamber C, toV increase the draught. The shoulder n formed in each channel a by the widening, as well asthe shoulder' formed in the openings b by the plates e', prevents the gas from moving towards the outer ends of the chambers c. The combined gas and air are lighted as soon as they enter the chamber C, and roasts .the ore contained therein. I

The roasting by this process is very equal, as the fire can be regulated with great accuracy. And the quantity of air and gas can also be very exactly regulated to ores of different quality and composition; no parts will be burnt up, nor will any romain raw in the centre. i f I To 'liberate the ore from the sulphur and arsenic, steam is introduced to the orc while it is heated. Water is forced into the tube e at its outer end, and as the tube is red hot the Water will therein be converted into steam. Said steam enters the chamber C through the holes in the pipe e, and comes in contact with the ore in a superheated condition. Combining with the sulphur of the ore, the steam is converted into sulphuretted hydrogen gas. The steam has also the effect t Vequalize and modify the heat in the kiln, thereby equalizing the'.

roasting process. As the sulphur is now contained in the furnace in the form of S H, it might again he taken up by the ores, by reducing the oxidized iron ofthe same, and thereby freeing they hydrogen. To prevent this, the channels d nl are arranged. Through the same atmospheric air is conducted into the chamber C, and burns the S H, converting the same into sulphurous acid, which is innoxious, as it will not combine with` the iron. The desulphurizing process is thus very complete, and its val `as been ytested by many experiments. The

channels d are provided with gates o, to regulate the ow of the air. The roasted ores are extracted through the channels j'. For magnetic ore, it would be well to have water poured over it while it is still glowing; thereby it crumhles, and the pounding is facilitated. The ores are now ready forthc reducing-furnace.

By the use ofthe pipe e the use of alboiler for creating steam is dispensed with, and the cost of the apparatns as well as ofl the operation is thereby greatly reduced.

Heretofore boilers were arranged outside of the kiln for creating the steam for desulphurizing purposesi By my device the heat in the kiln is utilized and equalized, and thereby improved for creating the steam for desulphurizing'the ore. I I claim as new, and desire to secure by Letters Patent-'- 1. The arrangement of the channels a, b, and d within 'the kiln A B, for conducting gas and air to the ore, substantially as herein shown and described. p 4

2. The perforated pipe When arranged in the lower part B of the kiln, in combination with the channels d d, made as set forth.

3. The process herein shown and described of roasting ore by means of gases discharged from distant res of any kind of fuel, as described. I

4. The process herein shown and described of desulphurizing the ore while roasting the same, by conducting' water into the pipe e, whereby the use of a steam-boiler is dispensed with, andby combining the steam produced from the water with atmospheric air, as and for the purpose set forth.

ALOIS TIIOMA.

Witnesses z l 'WM. F. MoNAMAnA, ALEX. F. ROBERTS. 

